Sunitinib and Pterostilbene Combination Treatment Exerts Antitumor Effects in Gastric Cancer via Suppression of PDZD8

Pterostilbene suppresses gastric cancer proliferation and metastasis by inhibiting oncogenic JAK2/STAT3 signaling: In vitro and in vivo therapeutic intervention

BACKGROUND

Gastric cancer (GC) represents a significant health burden with dire prognostic implications upon metastasis and recurrence. Pterostilbene (PTE) has been proven to have a strong ability to inhibit proliferation and metastasis in other cancers, while whether PTE exhibits anti-GC activity and its potential mechanism remain unclear.

PURPOSE

To explore the efficacy and potential mechanism of PTE in treating GC.

METHODS

We employed a comprehensive set of assays, including CCK-8, EdU staining, colony formation, flow cytometry, cell migration, and invasion assays, to detect the effect of PTE on the biological function of GC cells in vitro. The xenograft tumor model was established to evaluate the in vivo anti-GC activity of PTE. Network pharmacology was employed to predict PTE's potential targets and pathways within GC. Subsequently, Western blotting, immunofluorescence, and immunohistochemistry were utilized to analyze protein levels related to the cell cycle, EMT, and the JAK2/STAT3 pathway.

RESULTS

Our study demonstrated strong inhibitory effects of PTE on GC cells both in vitro and in vivo. In vitro, PTE significantly induced cell cycle arrest at G0/G1 and S phases and suppressed proliferation, migration, and invasion of GC cells. In vivo, PTE led to a dose-dependent reduction in tumor volume and weight. Importantly, PTE exhibited notable safety, leaving mouse weight, liver function, and kidney function unaffected. The involvement of the JAK2/STAT3 pathway in PTE's anti-GC effect was predicted utilizing network pharmacology. PTE suppressed JAK2 kinase activity by binding to the JH1 kinase structural domain and inhibited the downstream STAT3 signaling pathway. Western blotting confirmed PTE's inhibition of the JAK2/STAT3 pathway and EMT-associated protein levels. The anti-GC effect was partially reversed upon STAT3 activation, validating the pivotal role of the JAK2/STAT3 signaling pathway in PTE's activity.

CONCLUSION

Our investigation validates the potent inhibitory effects of PTE on the proliferation and metastasis of GC cells. Importantly, we present novel evidence implicating the JAK2/STAT3 pathway as the key mechanism through which PTE exerts its anti-GC activity. These findings not only establish the basis for considering PTE as a promising lead compound for GC therapeutics but also contribute significantly to our comprehension of the intricate molecular mechanisms underlying its exceptional anti-cancer properties.

Pterostilbene and 6-shogaol exhibit inhibitory effects on sunitinib resistance and motility by suppressing the RLIP76-initiated Ras/ERK and Akt/mTOR pathways in renal cancer cells

Sunitinib (SUN) is the first-line targeted therapeutic drug for advanced renal cell carcinoma (RCC). However, SUN resistance is frequently observed to result in tumor metastasis, with a poor survival rate. Therefore, finding an effective and safe adjuvant to reduce drug resistance is important for RCC treatment. Pterostilbene (PTE) and 6-shogaol (6-S) are natural phytochemicals found in edible sources and have potential applications against various cancers. However, the biological mechanisms of PTE and 6-S in SUN-resistant RCC are still unclear. Accordingly, this study investigated the regulatory effects of PTE and 6-S on cell survival, drug resistance, and cell invasion in 786-O and SUN-resistant 786-O (786-O SUNR) cells, respectively. The results demonstrated that PTE and 6-S induced apoptosis in both cell lines by upregulating the Bax/Bcl-2 ratio. Additionally, PTE and 6-S increased SUN sensitivity by inhibiting the expression of the RLIP76 transport protein, reduced cell invasion and downregulated MMP expression in both 786-O and 786-O SUNR cells. Mechanistically, PTE, and 6-S significantly and dose-dependently suppressed the RLIP76-initiated Ras/ERK and Akt/mTOR pathways. In summary, PTE and 6-S induce apoptosis, enhance SUN sensitivity, and inhibit migration in both 786-O and 786-O SUNR cells. These novel findings demonstrate the potential of PTE and 6-S as target therapeutic adjuvants for RCC treatment.

Involvement of Ferroptosis Induction and Oxidative Phosphorylation Inhibition in the Anticancer-Drug-Induced Myocardial Injury: Ameliorative Role of Pterostilbene

Patients with cancer die from cardiac dysfunction second only to the disease itself. Cardiotoxicity caused by anticancer drugs has been emphasized as a possible cause; however, the details remain unclear. To investigate this mechanism, we treated rat cardiomyoblast H9c2 cells with sunitinib, lapatinib, 5-fluorouracil, and cisplatin to examine their effects. All anticancer drugs increased ROS, lipid peroxide, and iron (II) levels in the mitochondria and decreased glutathione peroxidase-4 levels and the GSH/GSSG ratio. Against this background, mitochondrial iron (II) accumulates through the unregulated expression of haem oxygenase-1 and ferrochelatase. Anticancer-drug-induced cell death was suppressed by N-acetylcysteine, deferoxamine, and ferrostatin, indicating ferroptosis. Anticancer drug treatment impairs mitochondrial DNA and inhibits oxidative phosphorylation in H9c2 cells. Similar results were observed in the hearts of cancer-free rats treated with anticancer drugs in vitro. In contrast, treatment with pterostilbene inhibited the induction of ferroptosis and rescued the energy restriction induced by anticancer drugs both in vitro and in vivo. These findings suggest that induction of ferroptosis and inhibition of oxidative phosphorylation are mechanisms by which anticancer drugs cause myocardial damage. As pterostilbene ameliorates these mechanisms, it is expected to have significant clinical applications.

Pterostilbene Induces Apoptosis from Endoplasmic Reticulum Stress Synergistically with Anticancer Drugs That Deposit Iron in Mitochondria

Anticancer agents are playing an increasing role in the treatment of gastric cancer (GC); however, novel anticancer agents have not been fully developed. Therefore, it is important to investigate compounds that improve sensitivity to the existing anticancer drugs. We have reported that pterostilbene (PTE), a plant stilbene, enhances the antitumor effect of low doses of sunitinib in gastric cancer cells accumulating mitochondrial iron (II) (mtFe) at low doses. In this study, we investigated the relationship between the mtFe deposition and the synergistic effect of PTE and different anticancer drugs. For this study, we used 5-fluorouracil (5FU), cisplatin (CPPD), and lapatinib (LAP), which are frequently used in the treatment of GC, and doxorubicin (DOX), which is known to deposit mtFe. A combination of low-dose PTE and these drugs suppressed the expression of PDZ domain-containing 8 (PDZD8) and increased mtFe accumulation and mitochondrial H2O2. Consequently, reactive oxygen species-associated hypoxia inducible factor-1α activation induced endoplasmic reticulum stress and led to apoptosis, but not ferroptosis. In contrast, 5FU and CDDP did not show the same changes as those observed with PTE and DOX or LAP, and there was no synergistic effect with PTE. These results indicate that the combination of PTE with iron-accumulating anticancer drugs exhibits a strong synergistic effect. These findings would help in developing novel therapeutic strategies for GC. However, further clinical investigations are required.

Relevance of the endoplasmic reticulum-mitochondria axis in cancer diagnosis and therapy

Dynamic interactions between organelles are responsible for a variety of intercellular functions, and the endoplasmic reticulum (ER)-mitochondrial axis is recognized as a representative interorganelle system. Several studies have confirmed that most proteins in the physically tethered sites between the ER and mitochondria, called mitochondria-associated ER membranes (MAMs), are vital for intracellular physiology. MAM proteins are involved in the regulation of calcium homeostasis, lipid metabolism, and mitochondrial dynamics and are associated with processes related to intracellular stress conditions, such as oxidative stress and unfolded protein responses. Accumulating evidence has shown that, owing to their extensive involvement in cellular homeostasis, alterations in the ER-mitochondrial axis are one of the etiological factors of tumors. An in-depth understanding of MAM proteins and their impact on cell physiology, particularly in cancers, may help elucidate their potential as diagnostic and therapeutic targets for cancers. For example, the modulation of MAM proteins is utilized not only to target diverse intracellular signaling pathways within cancer cells but also to increase the sensitivity of cancer cells to anticancer reagents and regulate immune cell activities. Therefore, the current review summarizes and discusses recent advances in research on the functional roles of MAM proteins and their characteristics in cancers from a diagnostic perspective. Additionally, this review provides insights into diverse therapeutic strategies that target MAM proteins in various cancer types.

Pterostilbene alleviates abdominal aortic aneurysm via inhibiting macrophage pyroptosis by activating the miR-146a-5p/TRAF6 axis

Pterostilbene (PTE), a natural stilbene found in blueberries and several varieties of grapes, has several pharmacological activities, including anti-inflammatory and antioxidative activities. However, its role in abdominal aortic aneurysm (AAA), which is a severe inflammatory vascular disease, remains incompletely understood. In this study, we investigated the protective effects of natural stilbene PTE on AAA formation and the underlying mechanism. Two AAA mouse models (Ang II-induced model and PPE-induced model) were used to examine the effect of PTE on AAA formation. We showed that PTE administration attenuated AAA formation in mice. Furthermore, we found that PTE significantly inhibited inflammatory responses in mouse aortas, as PTE suppressed macrophage pyroptosis and prevented macrophage infiltration in aortas, resulting in reduced expression of pro-inflammatory cytokines in aortas. We also observed similar results in LPS + ATP-treated Raw 264.7 cells (a macrophage cell line) and primary peritoneal macrophages in vitro. We showed that pretreatment with PTE restrained inflammatory responses in macrophages by inhibiting macrophage pyroptosis. Mechanistically, miR-146a-5p and TRAF6 interventions in vivo and in vitro were used to investigate the role of the miR-146a-5p/TRAF6 axis in the beneficial effect of PTE on macrophage pyroptosis and AAA. We found that PTE inhibited macrophage pyroptosis by miR-146a-5p-mediated suppression of downstream TRAF6 expression. Moreover, miR-146a-5p knockout or TRAF6 overexpression abrogated the protective effect of PTE on macrophage pyroptosis and AAA formation. These findings suggest that miR-146a-5p/TRAF6 axis activation by PTE protects against macrophage pyroptosis and AAA formation. PTE might be a promising agent for preventing inflammatory vascular diseases, including AAA.

Integrated analysis of single-cell and bulk RNA-sequencing reveals the poor prognostic value of ABCA1 in gastric adenocarcinoma

PURPOSE

ATP-binding cassette A1 (ABCA1) is a potential prognostic marker for various tumor types. However, the biological effects and prognostic value of ABCA1 in gastric adenocarcinoma (GAC) remain unknown.

METHODS

GAC-associated single-cell RNA and bulk RNA-sequencing (bulk-seq) data were obtained from the Gene Expression Omnibus and The Cancer Genome Atlas databases, respectively. The differential expression of ABCA1 between GAC and normal gastric tissues was analyzed based on the bulk-seq data. Additionally, the relationship between ABCA1 expression and various clinicopathological features was explored. Furthermore, Kaplan-Meier survival and Cox regression analyses were performed to establish the prognostic value of ABCA1. The relationships between ABCA1 expression and anti-tumor drug sensitivity and immune checkpoints were also explored. Finally, the biological functions of ABCA1 were evaluated at the single-cell level, and in vitro studies were performed to assess the effects of ABCA1 on GAC cell proliferation and invasion.

RESULTS

ABCA1 expression is significantly elevated in GAC samples compared with that in normal gastric tissues. Clinical features and survival analysis revealed that high ABCA1 expression is associated with poor clinical phenotypes and prognosis, whereas Cox analysis identified ABCA1 as an independent risk factor for patients with GAC. Furthermore, high ABCA1 expression suppresses sensitivity to various chemotherapeutic drugs, including cisplatin and mitomycin, while upregulating immune checkpoints. ABCA1-overexpressing macrophages are associated with adverse clinical phenotypes in GAC and express unique ligand-receptor pairs that drive GAC progression. In vitro, ABCA1-knockdown GAC cells exhibit significantly inhibited proliferative and invasive properties.

CONCLUSION

High ABCA1 expression promotes an adverse immune microenvironment and low survival rates in patients with GAC. Furthermore, ABCA1 and ABCA1-producing macrophages may serve as novel molecular targets in GAC treatment.

Potential Chemopreventive Role of Pterostilbene in Its Modulation of the Apoptosis Pathway

Cancer incidence keeps increasing every year around the world and is one of the leading causes of death worldwide. Cancer has imposed a major burden on the human population, including the deterioration of physical and mental health as well as economic or financial loss among cancer patients. Conventional cancer treatments including chemotherapy, surgery, and radiotherapy have improved the mortality rate. However, conventional treatments have many challenges; for example, drug resistance, side effects, and cancer recurrence. Chemoprevention is one of the promising interventions to reduce the burden of cancer together with cancer treatments and early detection. Pterostilbene is a natural chemopreventive compound with various pharmacological properties such as anti-oxidant, anti-proliferative, and anti-inflammatory properties. Moreover, pterostilbene, due to its potential chemopreventive effect on inducing apoptosis in eliminating the mutated cells or preventing the progression of premalignant cells to cancerous cells, should be explored as a chemopreventive agent. Hence, in the review, we discuss the role of pterostilbene as a chemopreventive agent against various types of cancer via its modulation of the apoptosis pathway at the molecular levels.

Berberine Induces Combined Cell Death in Gastrointestinal Cell Lines

Berberine (BBR) is a plant alkaloid that has various biological activities. The effects of BBR on gastrointestinal cancer (GIC) have also been investigated and anti-tumor effects such as induction of cell death have been reported. However, the mechanism of BBR-induced cell death has not been fully elucidated. To this end, we investigated the effects of BBR using three GIC cell lines. Our analyses revealed that BBR inhibited cell proliferation, invasion, sphere formation, and anticancer drug resistance in all of the cell lines. BBR also induced an increase in mitochondrial superoxide, lipid peroxide and Fe2+ levels, decreased mitochondrial membrane potential and respiration, decreased glutathione peroxidase 4 expression and glutathione and induced Parkin/PINK1-associated mitophagy. BBR, as well as rotenone, inhibited mitochondrial complex I and enhanced complex II, which were associated with autophagy, reactive oxidative species production, and cell death. Inhibition of complex II by malonate abrogated these changes. BBR-induced cell death was partially rescued by ferrostatin-1, deferoxamine, Z-VAD-FMK, and ATG5 knockdown. Furthermore, oral administration of BBR significantly reduced tumor weight and ascites in a syngeneic mouse peritoneal metastasis model using CT26 GIC cells. These findings suggest that BBR induced a combined type of cell death via complex I inhibition and autophagy. The marked anti-tumor and anti-stemness effects are expected to be useful as a new cell death-inducing agent for the treatment of GIC.

Metal-dependent programmed cell death-related lncRNA prognostic signatures and natural drug sensitivity prediction for gastric cancer

Background: Gastric cancer is one of the most important malignancies with poor prognosis. Ferroptosis and cuproptosis are newly discovered metal-dependent types of programmed cell death, which may directly affect the outcome of gastric cancer. Long noncoding RNAs (lncRNAs) can affect the prognosis of cancer with stable structures, which could be potential prognostic prediction factors for gastric cancer.

Methods: Differentially expressed metal-dependent programmed cell death (PCD)-related lncRNAs were identified with DESeq2 and Pearson’s correlation analysis. Through GO and KEGG analyses and GSEA , we identified the potential effects of metal-dependent PCD-related lncRNAs on prognosis. Using Cox regression analysis with the LASSO method, we constructed a 12-lncRNA prognostic signature model. Also, we evaluated the prognostic efficiency with Kaplan–Meier (K-M) survival curve, receiver operating characteristic (ROC) curve, and decision curve analysis (DCA) methods. The sensitivities for antitumor drugs were then predicted with the pRRophetic method. Also, we discuss Chinese patent medicines and plant extracts that could induce metal-dependent programmed cell death.

Results: We constructed a metal-dependent PCD-related lncRNA-gene co-expression network. Also, a metal-dependent PCD-related gastric cancer prognostic signature model including 12 lncRNAs was constructed. The K-M survival curve revealed a poor prognosis in the high-risk group. ROC curve analysis shows that the AUC of our model is 0.766, which is better than that of other published models. Moreover, the half-maximum inhibitory concentration (IC50) for dasatinib, lapatinib, sunitinib, cytarabine, saracatinib, and vinorelbine was much lower among the high-risk group.

Conclusion: Our 12 metal-dependent PCD-related lncRNA prognostic signature model may improve the OS prediction for gastric cancer. The antitumor drug sensitivity analysis results may also be helpful for individualized chemotherapy regimen design.

The role of cuproptosis-related gene in the classification and prognosis of melanoma

Background

Melanoma, as one of the most aggressive and malignant cancers, ranks first in the lethality rate of skin cancers. Cuproptosis has been shown to paly a role in tumorigenesis, However, the role of cuproptosis in melanoma metastasis are not clear. Studying the correlation beteen the molecular subtypes of cuproptosis-related genes (CRGs) and metastasis of melanoma may provide some guidance for the prognosis of melanoma.

Methods

We collected 1085 melanoma samples in The Cancer Genome Atlas(TCGA) and Gene Expression Omnibus(GEO) databases, constructed CRGs molecular subtypes and gene subtypes according to clinical characteristics, and investigated the role of CRGs in melanoma metastasis. We randomly divide the samples into train set and validation set according to the ratio of 1:1. A prognostic model was constructed using data from the train set and then validated on the validation set. We performed tumor microenvironment analysis and drug sensitivity analyses for high and low risk groups based on the outcome of the prognostic model risk score. Finally, we established a metastatic model of melanoma.

Results

According to the expression levels of 12 cuproptosis-related genes, we obtained three subtypes of A₁, B₁, and C₁. Among them, C₁ subtype had the best survival outcome. Based on the differentially expressed genes shared by A₁, B₁, and C₁ genotypes, we obtained the results of three gene subtypes of A₂, B₂, and C₂. Among them, the B₂ group had the best survival outcome. Then, we constructed a prognostic model consisting of 6 key variable genes, which could more accurately predict the 1-, 3-, and 5-year overall survival rates of melanoma patients. Besides, 98 drugs were screened out. Finally, we explored the role of cuproptosis-related genes in melanoma metastasis and established a metastasis model using seven key genes.

Conclusions

In conclusion, CRGs play a role in the metastasis and prognosis of melanoma, and also provide new insights into the underlying pathogenesis of melanoma.